The article entitled “Compositional and structural properties of pulsed laser deposited ZnS:Cr films” has been published in Applied Physics A: Materials and Processing. The article is available from the publication menu.
As you might know, ZnS:Cr is a proposed intermediate band material, and we have deposited it by pulsed laser deposition. In this recent article we present a detailed study of the properties of ZnS:Cr films. The purpose is to understand how the structure of ZnS changes when we incorporate high amount of Cr in the ZnS lattice. In addition, we have studied the chemistry and composition of the deposited films by X-ray photoelectron spectroscopy. The paper presents an elaborate XRD and TEM study, and this study can lead to a better understanding of the Cr energy levels in the ZnS bandgap.
Our recent article entitled “Resonant photoemission spectroscopy for intermediate band materials” is published in Applied Physics Letters (107, 192104 (2015); doi: 10.1063/1.4935536):
We have studied Cr-doped ZnS films for application in intermediate band solar cells. The goal was to understand the origin of intermediate bands in doped ZnS. In the article, we show that the intermediate-band can be characterized using resonant photoemission spectroscopy, revealing the filling and specific orbital character of the states contributing to the resonant photoemission signal. The methodology can be widely extended to a large variety of materials, providing useful information towards engineering of high efficiency intermediate band solar cells and of other optoelectronic devices. More information are available in this presentation.
Our recent article entitled “Pulsed laser ablation and deposition of ZnS:Cr” is published in Thin Solid Films and is available online.
The article is presenting a method by which various dopant concentrations can be achieved using a single target by pulsed laser deposition. Varying doping/composition range is normally not achieved using a single target in pulsed laser deposition. Therefore, the focus of the article is describing various aspects of the method, such as target ablation study.
In addition, Cr doped ZnS films with high Cr content have spintronic and solar cell applications, for example as a potential intermediate band material. Growth of ZnS:Cr films with very high Cr content (up to 5 at.%) has not been reported previously. In the article, we report the growth and characterization of such Cr doped ZnS films.
Here are the highlights of the article:
- ZnS:Cr films (2-5 %) were deposited by pulsed laser deposition using a single target.
- Both the laser fluence and target pre-ablation affects the dopant concentration.
- The non-stoichiometric transfer was controlled in a reproducible manner.
Our recent article entitled “Molecular beam and pulsed laser deposition of ZnS:Cr for intermediate band solar cells” is now published in Solar Energy Materials & Solar Cells (Read the paper here). Here are the highlights of the paper:
- Cr-doped ZnS (ZnS:Cr) thin films with up to 7.5 at.% Cr, deposited by PLD and MBE are compared.
- The highly doped Cr:ZnS films were made for use in intermediate band solar cells.
- Similar optical properties, but different structural properties were achieved.
- The sub-bandgap absorption increased linearly with Cr concentration.
- Smoother and more textured films were obtained by PLD, compared to MBE.
Keywords: Pulsed laser deposition; Molecular beam epitaxy; Optical properties; Intermediate band solar cell; Doping and alloying; Transition-metal-doped semiconductor
I am going to participate in the 17th international conference on II-VI compounds and related materials, and will present a work entitled “Highly Cr-doped ZnS for intermediate band solar cells”. The conference will be held in Paris between 13 to 18th of September 2015. I would be glad to meet people working on growth and characterization of un-doped and doped ZnS and other II-VI compounds.
The Scope of the conference (from conference website)
The II-VI compounds provide a variety of unique optical, electrical and magnetic properties. The Conference will then cover all the aspects of basic and applied research, laying special emphasis on unique physical and material properties of II-VI compounds, related materials and nanostructures. A particular attention will be given to new trends and pioneering directions, as well as to new materials and devices.
The conference will give also the opportunity to review the most important achievements in practical applications of II-VI compounds in mid-infrared, visible and UV range detectors, optoelectronic devices…
It is an international forum aimed to review and stimulate the progress in basic and applied research on II-VI semiconductors and related materials, to facilitate the exchange of new ideas and to establish new scientific contacts.
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